Aotearocumella acantha, Gerken, 2012

Gerken, Sarah, 2012, 3524, Zootaxa 3524, pp. 1-124 : 6-9

Aotearocumella acantha n. sp.

Figures 2–3

Type material. Holotype subadult female, NIWA 80720 , paratype subadult female, NIWA 80721 , 40.1277°S, 170.2140°E – 40.1352°S, 170.2090°E, 803–805 m, 5 June 2007 . Paratype subadult male, dissected, NIWA 80722 , 0705 /160.

Other material examined. 5 subadult females, NIWA 79382 , 44.4862°S, 177.1413°E – 44.4841°S, 177.1416°E, 1235–1239 m, 6 April 2007 . 1 ovigerous female, 1 subadult female, 1 juvenile, NIWA 79383 , 44.4862°S, 177.1413°E – 44.4841°S, 177.1416°E, 1235–1239 m, 6 April 2007 .

Diagnosis. Females and subadult males. Carapace, pereonites and pleonites covered in fine spines, no setae; eyelobe absent; pseudorostral lobes not dorsally directed. Uropod peduncles 1.9 times pleonite 6 length. Male. Adult unknown.

Description of female.

Holotype subadult female, 2.5 mm, NIWA 80720 . Paratype subadult female, 2.4 mm, NIWA 80721 . Carapace covered in fine spines, no setae; pseudorostral lobes not dorsally directed, 0.8 times carapace length; eyelobe absent. Pereonites with spines. Pleonites with spines, some arranged in rows, including two rows laterally ( Figures 2A–B) .

Description of subadult male.

Paratype subadult male, 2.5 mm, NIWA 80711. Carapace as in female.

Antennule peduncle article 1 longest, unarmed; article 2 0.8 times article 1 length, with 2 pedunculate setae; article 3 1.1 times article 2 length, unarmed; main flagellum of 4 articles, with 2 aesthetascs and simple seta; accessory flagellum of 2 articles, with 3 simple setae ( Figure 2C).

Maxillule with 2 endites; outer endite with double row of simple setae; inner endite with 1 simple, 1 microserrate and 1 dentate setae; palp with 2 microserrate setae ( Figure 2D).

Maxilla with 3 endites; broad endite with row of simple setae distally, medial corner with 1 simple and 2 pappose setae, medial row of setae; medial narrow endite with 4 microserrate setae terminally; distal narrow endite with 5 microserrate setae terminally; both narrow endites extend only to distal margin of broad endite ( Figure 2E).

Maxilliped 1 basis produced as lobe, with 5 simple, 2 hook and 1 tricuspid setae; ischium absent; merus 0.1 times basis length, unarmed; carpus 2.6 times merus length, with 3 simple, 3 comb-like and 1 plumose setae; propodus 0.3 times carpus length, unarmed; dactylus 0.8 times propodus length, with 5 simple setae ( Figure 2F).

Maxilliped 2 basis 0.8 times length of all other articles together, with 1 simple and 1 plumose setae, lateral margin lined with fine hair-like setae; ischium absent; merus 0.4 times basis length, with plumose seta; carpus 0.6 times merus length, with pappose seta; propodus 1.1 times carpus length, with 1 plumose and 3 pappose setae; dactylus 0.6 times propodus length, with pappose seta, terminal seta microserrate, lateral margin produced as 2 strong teeth ( Figure 2G).

Maxilliped 3 basis 1.4 times length of all other articles together, with 3 plumose setae medially, 2 plumose setae at distal corner; ischium 0.06 times basis length, unarmed; merus 1.7 times ischium length, with pappose seta medially, plumose seta laterally; carpus 2.2 times merus length, with 3 pappose setae medially, plumose seta laterally; propodus 0.9 times carpus length, with 2 pappose setae; dactylus 0.6 times propodus length, with 2 simple setae terminally; exopod 0.8 times basis length, basal article unarmed, flagellum with plumo-annulate setae ( Figure 3A).

Pereopod 1 basis 0.9 times length of all other articles together, with 2 simple setae, lateral margin produced as strong teeth distally; ischium 0.08 times basis length, with simple seta; merus 2.0 times ischium length, with sunoke seta; carpus 2.7 times merus length, with 3 simple setae; propodus 0.8 times carpus length, with 2 simple setae; dactylus 0.7 times propodus length, with 3 simple setae terminally; exopod 0.8 times basis length, basal article unarmed, flagellum with plumo-annulate setae ( Figure 3B).

Pereopod 2 basis 0.8 times length of all other articles together, with simple seta, lateral margin produced as strong teeth; ischium 0.1 times basis length, with simple seta; merus 2.3 times ischium length, with simple seta; carpus 1.7 times merus length, with 2 simple and 2 microserrate setae; propodus 0.5 times carpus length, with simple seta; dactylus 2.5 times propodus length, with 3 simple setae, terminal seta simple; exopod 1.3 times basis length, basal article with simple seta, flagellum with plumo-annulate setae ( Figure 3C).

Pereopod 3 basis 1.1 times length of all other articles together, with 2 simple and 1 plumose setae; ischium 0.1 times basis length, with 2 simple setae; merus 1.5 times ischium length, with simple seta; carpus 1.6 times merus length, with annulate seta; propodus 0.5 times carpus length, with annulate seta; dactylus 0.7 times propodus length, with 2 simple setae terminally ( Figure 3D).

Pereopod 4 basis 0.8 times length of all other articles together, with 3 simple setae; ischium 0.2 times basis length, with simple seta; merus 1.3 times ischium length, with simple seta; carpus 2.0 times merus length, with 1 plumose and 1 annulate setae; propodus 0.5 times carpus length, with annulate seta; dactylus 0.6 times propodus length, with 2 simple setae terminally ( Figure 3E).

Pereopod 5 with plumose seta; ischium unarmed; merus 1.8 times ischium length, unarmed; carpus 1.9 times merus length, with 1 simple and 1 plumose setae; propodus 0.4 times carpus length, with annulate seta; dactylus 0.8 times propodus length, with 2 simple setae terminally ( Figure 3F).

Uropod peduncles 1.9 times pleonite 6 length, with 3 simple setae, with 2 rows of strong teeth. Uropod endopod uniarticulate, 0.8 times peduncle length, with 3 microserrate setae medially, medial margin produced as strong teeth, simple with single subterminal setule seta laterally, terminal seta simple with single subterminal setule. Uropod exopod of 2 articles, 0.9 times length of endopod; article 1 0.2 times article 2 length, with simple seta; article 2 with 2 simple setae, terminal seta simple ( Figure 3G).

Etymology. The new species is named from the Latin acanthus, meaning prickles or thorns, in reference to the spines that cover the carapace, pereonites and pleonites.

Remarks. This species is unlike Aotearocumella watlingi and A. echinoseta in that there are no long setae on the carapace, pereon or pleon.